Tea party-backed Sen. Rand Paul (R-Ky.) isn’t sure that congressional Republicans have the guts to make the big budget cuts they’ve promised and, he said, members of the movement are becoming frustrated.

“There’s a disconnect between Republicans who want a balanced budget but aren’t maybe yet brave enough to talk about the cuts to come,” the freshman senator said in an interview with ABC News, responding to the spending plan released Thursday by the House Budget Committee chairman, Rep. Paul Ryan (R-Wis.), which would cut non-defense discretionary spending by $58 billion for the rest of fiscal 2011.

“I go to a tea party, and you know what they say to me? ‘It’s not enough. It’s not enough. Where’s the other trillion you need?’” Paul said. He’s offered his own budget plan that would cut spending by $500 billion this year, including an end to all foreign aid and a dramatic reduction to the U.S. Department of Education’s budget.

Paul, son of libertarian Rep. Ron Paul (R-Texas), said he is a “true believer,” determined to stand by his tea party values and not get bogged down falling in line with the GOP.

“There are always problems in our nation’s capital that are more important than party affiliation, and I will always believe that,” Paul said. “It’s not necessarily tea party versus Republican Party, but I would say that if you ask me what’s more important — tackling our nation’s deficit, our nation’s debt problems or being a Republican — I would say tackling the debt.”

Paul also defended his calls to end aid to Israel, saying they’re just part of his bigger efforts at fiscal responsibility. “I’m not singling out Israel. I support Israel. I want to be known as a friend of Israel, but not with money you don’t have,” he said. “We can’t just borrow from our kids’ future and give it to countries, even if they are our friends.”

And, he said, giving money to the country is especially unwise considering Israel’s relative wealth. “I think they’re an important ally, but I also think that their per capita income is greater than probably three-fourths of the rest of the world,” he said. “Should we be giving free money or welfare to a wealthy nation? I don’t think so.”